﻿// Copyright 2004-2011 Castle Project - http://www.castleproject.org/
// 
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// 
//     http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#region 导入名称空间

using System.Reflection;
using LightWork.DynamicProxy.Generators;
using LightWork.DynamicProxy.Generators.Emitters;
using LightWork.DynamicProxy.Generators.Emitters.SimpleAST;

#endregion

namespace LightWork.DynamicProxy.Contributors
{
    public class MinimialisticMethodGenerator : MethodGenerator
    {
        public MinimialisticMethodGenerator(MetaMethod method, OverrideMethodDelegate overrideMethod)
            : base(method, overrideMethod)
        {
        }

        protected override MethodEmitter BuildProxiedMethodBody(MethodEmitter emitter, ClassEmitter @class,
            ProxyGenerationOptions options, INamingScope namingScope)
        {
            InitOutParameters(emitter, MethodToOverride.GetParameters());

            if (emitter.ReturnType == typeof(void))
                emitter.CodeBuilder.AddStatement(new ReturnStatement());
            else
                emitter.CodeBuilder.AddStatement(new ReturnStatement(new DefaultValueExpression(emitter.ReturnType)));

            return emitter;
        }

        private void InitOutParameters(MethodEmitter emitter, ParameterInfo[] parameters)
        {
            for (var index = 0; index < parameters.Length; index++)
            {
                var parameter = parameters[index];
                if (parameter.IsOut)
                    emitter.CodeBuilder.AddStatement(
                        new AssignArgumentStatement(new ArgumentReference(parameter.ParameterType, index + 1),
                            new DefaultValueExpression(parameter.ParameterType)));
            }
        }
    }
}